Riveting



Nov. 25, 1969 A. J. COLAUTTI ET AL 3,479,727

RIVETING- Original Filed Oct. 11, 1965 INVENTORS fi/Jer/ cfa/azzz' (5 BYone/a 75. 5.215111% .9 2 2 p A T TO R N E Y f :ii"ii-iii.. fi

PRIOR ART United States Patent Int. Cl. B23p 11/00 US. Cl. 29-444 2Claims ABSTRACT OF THE DISCLOSURE A controlled degree of looseness in arivet which provides a pivot for two relatively movable members isachieved by exerting an upsetting force on the rivet while resisting theforce by an abutment engaging the perimeter of the rivet head so thatthe head is sprung slightly by the upsetting force and then springs backto provide the desired degree of clearance.

This application is a division of our application Ser. No. 494,606,filed Oct. 11, 1965, now Patent No. 3,357,084, issued Dec. 12, 1967.

Our invention relates to a new method of riveting.

Conventional riveting methods include inserting a headed rivet throughapertures in the members being fastened and then upsetting the rivetwhile the head portion is held against an anvil surface. Thisconventional riveting method results in a tight riveted connection andis very undesirable in situations where a slight amount of tolerance orplay is desired in the riveted assembly.

It is, therefore, an object of the subject invention to provide ariveting method whereby a controlled amount of tolerance can be providedbetween the members joined in a riveted assembly.

In general, the invention features the use of an anvil having a cavitysized to support the outer perimeter of a rivet head and yet allow thecenter portion of the rivet head to be forced into the cavity uponactuation by a punch or other force-producing element. This distortingor dishing of the rivet head occurs prior to the upsetting of the rivetshank at the other end and results in a controlled amount of spring backup completion of the upsetting operation. It is this controlled springback which results in the amount of tolerance desired in the rivetedassembly.

Other objects, features and advantages of the subject invention willbecome obvious upon reference to the following detailed description andthe drawings depicting the preferred embodiment of the invention,wherein:

FIGURE 1 is an elevation view with parts in section showing a rivetedassembly accomplished by use of the apparatus and method of theinvention;

FIGURE 2 is an elevation view with parts in section of the apparatus ofthe invention as it is about to contact a rivet to result in a rivetedassembly;

FIGURE 3 is the same view as FIGURE 1 at the instant where the apparatusof the invention has dished the head of the rivet;

FIGURE 4 is the same view as FIGURE 3 at the point where the apparatushas upset the shank portion of the rivet; and

FIGURE 5 is a view of a conventional riveted assembly.

More particularly, the apparatus of the subject invention includes apunch and an anvil 12. The punch 10 may be of any suitable materialhaving properties sufiicient to withstand the forces developed in thistype of operation and may be actuated by any suitable manual orpower-driven mechanism (not shown). The punch 10 is seen to include ashank portion 14, a body portion 16, which is adapted to be connected tothe actuation means,

Patented Nov. 25, 1969 'ice and a work-contacting end 18. Thework-contacting end 18 includes force concentrating cross ribs 20 and 21which extend axially therefrom.

The anvil 12 may also be of any suitable material having propertiescapable of withstanding the force developed in such an operation. Theanvil 12 may also be of any suitable size and shape and is supported ona base 22. The work-contacting end of the anvil 12 is seen to have arecess 24 which has an annular stepped shoulder portion 26.

' A rivet 28 is shown passing through apertures in the members 30 and 32which are to be assembled. The members 30 and 32 may be any two deviceswhich are required to be assembled together. In this particularembodiment the member 30 is a lockbar plate and the member 32 an upperchannel in a seat adjusting mechanism for an automobile. This particularembodiment was chosen because it is a situation where it is desired tohave a controlled amount of tolerance between the lockbar plate and theupper channel to create a pivot permitting rotational movement of onerelative to the other in a plane normal to the axis of the rivet, butnot so as to allow rocking movement of one member relative to the other.

The rivet 28 is seen to include a relatively broad, flat head 34, anintermediate shank 36 extending through an aperture 38 in the member 30,and a lesser diameter shank 40 extending through an aperture 42 in themember 32.

The remaining discussion will be directed toward the operation of thesubject invention as seen in sequence from FIGURES 2 t0 3 t0 4 to l.

As seen in FIGURE 2, the rivet 28 has been inserted through the members30 and 32 and is resting on the stepped shoulder portion 26 in therecess 24 of the anvil 12. It can also be seen that the punch 10 hasbeen moved to a position where it is about to contact the end of theshank 40 of the rivet 28. Moving to FIGURE 3, it is seen that the crossribs 20 and 21 of the punch 10 contact the end of shank 40 of the rivet28 first, thereby concentrating the displacement force in the center ofthe rivet 28 and forcing the center portion of the head 34 into thecavity 24 until it bottoms on the lower surface 44. At this point it isseen that the intermediate shank 36 of the rivet 28 has been displaceddownwardly such that the member 32 is resting on the member 30. Movingto FIGURE 4, it is seen that once the head portion 34 of the rivet 28has bottomed on the surface 44 in the cavity 24, the force of the punch10 then upsets the shank portion 40 in a radial direction. At the pointshown in FIGURE 4 the members 30 and 32 are held tightly together underthe force of the punch 10 and the holding action of the anvil 12. Movingto FIGURE 1, it is seen that when the punch 10 and anvil 12 are removedfrom the assembly, the rivet head 34 springs back a predetermined andcontrolled amount to thereby move the intermediate shank 36 and create acontrolled amount of tolerance in the assembly between the members 30and 32. The amount of this spring back is a function of the depth of thecavity 24, the properties of the material of the rivet 28, and thedimensions of the rivet head 34. Therefore, the depth of the cavity 24should be designed for the maximum amount of tolerance expected betweenthe upper surface of the intermediate shoulder 36 and the upper surfaceof the member 30. Hence, the procedure just described results in ariveted assembly whereby two members are assembled together with acontrolled amount of tolerance built into the riveted assembly. Itshould be noted that the rivet head 34 does not have to bottom in thecavity 24 as it will still spring back an amount proportional to itsdisplacement. Additionally, it should be clear that the displacementsshown on the drawings are exaggerated for purposes of illustration.Furthermore, it is not es s ent ial that ashouldered rivet be used as asimple rivet with a shank of constant diameter would be likewise.operable under the method of this invention, 1

FIGURE 5 shows a conventional riveted assembly, whereby a rivet 46 ofthe same type as that used in the present invention holds members 48 and50 together. It can be seen that this conventional riveting methodresults in a tight riveted assembly. The only way a tolerance betweenthe members 48 and 50 can be assured in the conventional rivetingassembly is to use a rivet with the intermediate portion 52 beingslightly longer than the thickness of the member 48. If this differencein size could be controlled with exact precision, the desired tolerancesbetween the members 48 and 50 could be accom- 'plished with aconventional riveting operation. However, in modern-day high productionassembly operations, it is extremely expensive and virtually impossibleto control tolerances of assembly parts to the accuracy required toassure the desired tolerance between the members 48 and 50.

Hence, the conventional riveting method as shown in FIGURE 5 isextremely impractical for modern-day riveting assemblies wherein acontrolled amount of tolerance between the members being assembled isdesired.

The present invention provides a riveting method whereby a controlledamount of tolerance between the members being assembled can be rivetedinto the assembly regardless of slight variations in the size of therivet and the members being secured.

It should be clear to those skilled in the art to which it pertains thatthe present invention has many uses other than the embodiment shown anddescribed and that many changes and modifications may be made theretowithout departing from the scope of the invention.

We claim:. a

1. A method of providing a riveted joint of controlled tolerance betweentwo members having aligned apertures comprising the steps of:

providing a rivet having a shank and a head at one end of the shankextending radially from the shank, inserting the rivet through the saidapertures so as to engage the head against one said member, supportingthe head of the rivet only at its perimeter and concurrently exerting anaxial force on the other end of the shank, so that the head is dished bythe axial force exerted through the shank,

'upsetting the shank of the rivet against the other said member toprovide a riveted connection between the members,

and thereafter relieving the axial force to cause the head of the rivetto spring back from its dished condition and thereby create a controlledaxial looseness in the riveted connection.

.. 2. A method as recited in claim 1 in which the upsetting is effectedby the said axial force.

References Cited UNITED STATES PATENTS 1,610,664 12/1926 Ellison 294692,724,867 11/1955 Smith 29469 X 2,756,495 7/1956 Lathrop 29469 X2,997,716 8/1961 Huelster 227- X 3,013,272 12/1961 Barratt 227140 X3,209,446 10/1965 Nicholas 29444 X WAYNE A. MORSE, 111., PrimaryExaminer US. Cl. X.R. 29469, 526; 227-140

